Masking strip design



FIG. 1 is a perspective view of a masking strip design showing the new design;

FIG. 2 is a side view thereof;

FIG. 3 is an end view thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom view thereof.

In FIGS. 1, 2, 4, and 5, the masking strip design is shown broken away in two places in order to indicate indeterminate length. 

The ornamental design for a masking strip design, as shown and described. 